Electroless metal plating techniques for consolidation of incompetent formations

ABSTRACT

A method of depositing metal, for example, in order to consolidate an incompetent subsurface earth formation, by an electroless metal plating process using hydrogen phosphite ion containing compound as the reducing agent in the metal plating solution.

United States Patent Richardson [451 Aug. 22, 1972 [54] ELECTROLESS METAL PLATING TECHNIQUES FOR CONSOLIDATION OF INCOMPETENT FORMATIONS [72] Inventor: Edwin A. Richardson, Houston,

T .6 Us. [73] Assignee: Shell Oil Company, New York,

[22] Filed: Jan. 14, 1971 [21] Appl. No.: 106,563

Related US. Application Data [63] Continuation of Ser. No. 849,178, Aug. 11,

1969, abandoned.

[52] US. Cl ..166/292, 61/36 R, 106/1, 117/54, ll7/l23 B, l17/l 30E [51] Int. Cl. ..C23c 3/02, E02d 3/14, E2lb 33/138 [58] Field of Search..l66/292, 300; 106/1; 117/47 R, 117/49, 54, 123 B, 130 E, 130 C, 160; 61/36 Primary Examiner-Stephen J. Novosad Attorney-1'1. W. Coryell ABSTRACT A method of depositing metal, for example, in order to consolidate an incompetent subsurface earth formation, by an electroless metal plating process using hydrogen phosphite ion containing compound asthe reducing agent in the metal plating solution.

8 Clainm No FOR CONSOLIDATION OF INCOMPETENT FORMATIONS CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation of application Ser. No. 849,178, filed Aug. 11, 1969, and now abandoned.

BACKGROUND OF THE INVENTION In the U.S. Pat. Nos. 3,393,737, 3,438,440, 3,438,441 and pending applications Ser. No. 692,726 filed Dec. 27, 1967, now U.S. Pat. No. 3,500,926, and Ser. No. 705,907 filed Feb. 16, 1968, now U.S. Pat. No. 3,500,927 electroless metal plating techniques are described for consolidating unconsolidated formations and wherein it is disclosed that the process is generally superior to resin consolidation techniques for consolidating earth formations as described in such papers as Jr. Pet. Tech. May, 1966,'p. 545 entitled Review of Sand Consolidation Experience in Southern Louisiana J. L. Rike or Jr. Pet. Tech. December, 1961, paper entitled Large-Scale Laboratory Investigation of Sand Consolidation Techniques by W. 'F. Hoover, or Jr. Pet. Tech. Dec., 1966, p. 1,537 article entitled Studies of a New Process to Consolidate Oil Sands with Plastics by B. R. Treadway or as described in U.S. Pat. Nos. 3,412,796, 3,419,072, r 3,378,071, 3,373,813,- 3,310,311, 3,282,338 and the like. In essentially all of these resin consolidation processes for consolidating incompetent formations rigs are required, curing time is difficult to control, the resin coating or binding material is not resistant to temperature changes encountered in the treated formation or to water stability or the influence of corrosive acids and the like.- This results in costly operations of restrictive use and benefit and therefore makes the electroless metal consolidation techniques described inthe above-mentioned references more attractive since metal consolidated formations require no rig, the formations thus treated are not effected by temperature changes and are water stable and impart high compressive strength to such metallized consolidation formations.

As evidenced from the electroless metal plating solutions cited in the patents andpending applications cited above, as well as in U.S. Pat. Nos. 2,658,841, 2,690,403, 3,438,798 the reducing agent used in these reactions is generally a hypophosphite salt such as sodium hypophosphite (NaH,PO,). Also from the disclosure in these references the metalization rate is generally difficult to control and therefore various means are employed to control'the reaction in which buffers, accelerators, retarders, and the like are used particularly when temperature is a factor. Thus, depending on the temperature of the formation being consolidated, acidic or basic electroless metal plating solutions are used as noted from U.S. Pat. Nos. 3,438,440 and 3,438,441, and, in certain situations, the solution must be inhibited with certain organic compound e.g., sulfimide as described in copending application Ser. No. 840,826, filed July 10, 1969, now U.S. Pat. No. 3,586,524.

Therein the method comprises consolidating incompetent formations at low temperatures in the presence of an electroless basic metal plating solution under conditions of reduced stress by addition to the solution of a small amount of an organic sulfimide. Thus, it has been found that the addition of a small amount of metal plating solutions results in controlled metal deposition and consolidation of formations which are resistantto stress and hot fluid damage and in consolidating sands or coating materials at substantially normal room temperature, excellent uniform metal coatings are produced by using alkaline-plating solutions containing organic sulfimides such as saccharin. I r

-It has now been discovered that more efficient control of the electroless metal plating reaction at relatively high temperatures can be accomplished by the reduction of a nickel complex-by oxidation of phosphite ions, such as the hydrogen phosphite ion, (l-IPOJ to phosphate ions, such as the orthophosphate ion, (POJ Reduction of the nickel compound to nickel as a metalizing agent, such as a bonding agent, for the sand grains of an incompetent earth formation, in the presence of a hydrogen phosphite (HPOJ compound results in better reaction control at temperatures rang- .ing from about 250-400 F. For example, the reaction can be controlled to provide a compressive strength in the order of 20,000 to over 40,000 psi. in a consolidated mass of earth formation materials, such as sand.

This invention is uniquely advantageous in respect to problems encountered in'consolidating an incompetent subsurface earth formation that has a relatively high temperature. The invention is useful in connection with substantially any electroless metal plating process that is conducted at a relatively high temperature under a pressure sufficient to prevent an adversely high rate of vaporization of the plating solution. It is useful in plating metal on materials composing or contained ina permeable structure in which theplating solution can be contained or through which it can be flowed, e.g., a

heated autoclave, a hot tank or boiler tube, or the like.

It is particularly useful in plating metal on or in a permeable structure that contains or is'composed of material that is non-catalytic with respect to electroless metal plating, by means of a procedure in which a plurality of pore volumes of an activating solution is flowed through the structure ahead of a plurality of pore volumes of the plating solution. It is useful for depositing metal in order to provide a protective coating on a conduit, on the grains and intergranular bonding materials of consolidated earth formation, to distribute metal within a permeable mass, to plug the interstices of a permeable mass, etc.

PREFERRED EMBODIMENT OF THE INVENTION The activator solutions can be any of the activator solutions described in U.S. Pat. Nos. 3,393,737, 3,438,440 or 3,438,441 and include stannous chloride and/or palladium chloride solutions which may contain hydrazine and which solutions can be buffered with weak organic acids and their salts. Preferred activator solutions are shown in tables 1 and 2.

TABLE 1 Composition of Activator Solution (A Quantity per Barrel of Solution Water 40.7 gallons Sodium Acetate v 'Contains'IOJ-grama PdClJbblot'aictivatorsolution.

- 3, 900 dc Water .tion 1 or. 2, as well as 3-and 6), nickel ions are reduced by hydrogen phosphite ions (l-lPO,) as follows:

Adding e two separate I overall reaction:

Gum Arabic 1 20.6 gm:

l-lydrazine Hydrate 256 cc (or 400 cc of 35% (85%) hydrazine) Palladium Chloride 636 cc Solution NiSO.-6H,O Omit when v Buffers 90% Formic Acid or areUsed GlacialAcetic (as J needed for pH 4.4) -l60-320 cc Butters Fotmic Acid (90%) 640 cc Sodium Formate I "Ilba."

Acetic Acid (Glacial) 6.4 liters 10.5 lbs.

Note: Chemicals 1km: be added fwne in the a; listed with complete mixing and dissolving before adding the next chemical. II

Requires about l5 minutes to dissolve. I i Contains [.6 gma PdCl,, cc cone. HCl, 90 cc distilled or deionized water/100 cc PdCl solution. I J V a V B E I Activator Solutions 100 cc of Solution Comprising 919 cc Water .8 m d ies om 'i Containing 0,4/g'ram/l "f 'w 04 cc Hydrazine Hydrate (85% Solution) l.0 cc of a Solution Containing 1.6 Grams PdCL-ZHQ IOccConc. HCI I' a I 90 cc Water Add Glacial Acetic Acid to give pH 4.2

THE ELECTROLESS PLA'IING sownou In the present invention chemical reduction plat ing, referred to as electroless plating,a metallic'ion I in solution is reduced metal by A0 the required number of electrons;

' these electronsis the oxidation of another ion in solu source of Na Acetate- 3H,O

grams/liter 5 l .3 Glacial Acetic Acid I cc/liter r I HA pH 1 9.5 no.0 9.1 as as 5.6 Density-gramllcc L06 1.04 I I109- I Note: The phosphite should be added to avoid precipitation during miiiing. I I v Thus, the tvvo electrons for of a divalent metal ion to; the metal are supplied by'oxidation of a phosphit'eion to aphosphate ion. The reactions, as, given intheabove equation for. nickel, are aimv plified .in that the nickel ion may not be, present in f free form butasa complexion ammonia or glycolic acid, forexample-tocontrolthe reaction rate and/or to prevent precipitation of salts-in the solution.-

Also, the respective phosphite' and phosphate ions may I each be present in one or more ionimtionstates such I as (P0,; ,(HPOJ r (Biron-f r the ph p itei n nurod'..oir di rtuiroir o t Phosphate.

ions, depending onthe pH of the solution.

To achieve adherentdepositgthe reaction must be autocatalytic and to the surface. To.

initiate the reaction; on a non-catalytic surface, such as sand or glass, acatalyst such as palladium is tion which is referred to asthe agent. To, illustrate thesereactions in alkaline solution (table 3, solu- Composition of Solutions Component Solution Numberno. ncuno. no.no. no. 1f 23 4s 6 I 'll,O--celliter 792 695 :25 as: s60 :12 NiCl,-6l-l,0

grams/liter 37139.5 31.8373 37.: 41.1

' grams/liter 90.3 39.5 09.4 90.6 4. 5 5l.3

. NaH,PO,-H,O grams/C x 0.92 0.93

NlhCl-gramrlliter till-65.0 60.5 6L4 6L4 29.4% NH,- cclliter 92.6217 64.3 5L2 5 1.2 6L5 NaCitrate '2H,O I 615 tr m/ t 'eactions, we obtain the .B. Over-all reaction and standard potential adsorbed onthe surface prior t contact 'with the plating solution. vTo achieve consolidation of a-sa nd pack,

in a steam flood.

I A preferred plating is by the reduction of nickel complexed with amine bythe oxidation of hydrogen (HPOJ to phosphate I (POJ to the following reaction:

A. "Iii-Cell Ind standard mm I a s (HPO,),+ sol-r Po.-+'2H.o 2: I 1.12

Nahum."- 2e Ni 6Nl-l, (aq) 0.41

The over-all reaction is spontaneous at unit activities, as evidenced from the positive E value; the

is greatly shifted to the right under most,

' conditions The reaction is confined to the surface of a solid palladium or nickel catalyst and produces the typical electroless deposition of metal.

PROCEDURE FOR CARRYING OU'ITHE CONSOLIDATION tion are shown in table 4.

Experiments and their for consolidating forz mations by the electroless metal process of this inven- TABLE -l.l*]PE NIPPLE EXPERIMENTS 300 TO 350" I".

Procedure:

(1) No. 5 Sand (A.=2.0) in pipe nipple (600 psi. fluid pressure) ('2) H20 flush plus IPA flush plus H O flush (3) 500 cc. p-Zi-92 s Pd activator solution (4) Spacer it required (see below) (5) Plating solution (see code number below) (6) Buffer flush it used (see below) Results:

Plating Time of Run solution Bufier T F N' uting, No. pH Spacer flush F. (p.v./n1in.) (p.v.) t (mins.) Compressive strength extrapolated to inlet, p.s.l.

9. 1 None None 336 2. 1 140 68 High. 8.8 Note 0 ..do 336 4. 9 137 28 Note C- 336 2. 8 162 59 do 33 3.0 66 21 3. 0 159 53 High.

2. 2 159 71 -40,000 (19,000 in middle). 0. 84 114 135 High.

3. 3 112 36 Good-after -day exposure to hot distilled water flow at 550 F. 7.7 186 24 High.

F =flow rate through consolidated zone in pore volumes of consolidated zone/min. N =number of pore volumes of plating solution used (one porc volu1ne=pore volume of consolidated zone only).

(38.0 gaL/bbl. H2O, 23.1 lb./bbl. of NH4C1, 2.31% CllC. NHO4H (29.40 NHI) PH 9.3.

s (37.8 gal. field water plus Activator A; Table 1.) a

" lPA=Isopropyl Alcohol.

DISCUSSION OF THE RESULTS sHowN iN TABLE 4 A. Activation A colloidal palladium solution, A was found to be effective in this high-temperature range to activate the sand.

B. Spacers An induction period of a few minutes is required to start the plating reaction as evidenced by a small amount of undepleted plating solution which comes out of the system at the beginning of each test. This makes it unnecessary to use spacers to prevent loose metal solids from forming in the inlet tubing and plugging the inlet of the pack. This is shown by runs nos. 6 and 7; run no. 6 had no spacer between the activator solution and plating solution, yet appeared identical to run no. 7 which had a water spacer.

Best results occurred using a buffer as a spacer (run no. 5) but this is not believed to be necessary in practical applications.

C. Composition of Plating Solution The initial solutions employed (runs nos. 1 through 3) contained a small amount of hypophosphite to help initiate the reaction. However, this was not found to be necessary and (see runs nos. 5 through 9) its use was discontinued. No effort to optimize the amount of Ni and l-IPO was made and an arbitrary amount of 3 moles of l-IPO lmole Ni was used (except in run no. 4). There appears to be an excess HPO; at this ratio Since colorless (presumably nickel-free) solution was produced after a few minutes plating time in each run (unfortunately, run no. 4 plugged so Soon after starting the plating reaction that no information as to the utilization of I-IPO; could be obtained). It should be pointed out that Na HPO salt as used in these tests may not be commercially available; in this case a mixture of orthophosphorous acid H (NPO and NaOH may be more practical to employ.

The pH of the solution is critical in preventing precipitation before and during the plating reaction; at pH 8.8 (runs nos. 2, 3, and 4) much plugging was noted probably due to precipitation of (Ni) (PO in the inlet lines, etc.; at pH 9.1 (run no. 1) considerable loose solids were noted but not enough to seriously restrict fluid flow at the sand pack inlet; at pH 9.5 virtually no loose solids in the inlet were noted in any runs Very little gas (presumably H was observed in depleted effluent from each consolidation experiment. This small amount was completely dissolved, in the solution at 600 psi. This virtual absence of gas as a byproduct may indicate much higher efficiency for the utilization of HPO; than the ==30% assumed for experience with H PO; systems. This is also suggested by 5 a slight increase in pH withoccurs during plating (instead of a decrease as in (H,PO systems), indicating that little, if any, acid forms during the reaction. E. Compressive Strength Generally, the size of the consolidation zone in each run was too small to accurately determine this parameter. However, from visual inspection and noting the difficulty with which the consolidated zone was cored and sawed, it was evident that high compressive strength had developed at the inlet of the sand pack in most cases. However, in one case (run no. 6), the Size of the consolidation zone was sufiicient to obtain a measurement and the high values expected (20,000 to 40,000 psi) from the lack of gas phase present was confirmed. Also, one run (no. 8) was exposed to hot water flow at 550F for 10 days; no cracking developed and no loss of sand occurred. The consolidation was very good after the hot water treatment; however, there were some indications that the deposits were slightly degraded. Unfortunately the size of the consolidated zone in this test was too small to obtain accurate compressive strength measurements.

When no plugging due to trash or other extraneous material occurs at the inlet, the permeability loss may be estimated from the number of pore volumes of plating solution consumed in the consolidation. By this method, not more than 30 percent of the permeability was lost in run no. 1 and in runs nos. 5 through 9.

The plating solution at pH 9.5 (solution no. 1) appears to deplete without formation of any solids except on the metal surface as desired and hence no excessive permeability losses would be expected.

.about every 18F in the 300-350F range. This is approximately the same as thatfound for the hypophosphite (H,PO, system in the 100 to 200 range.

CONTROL OF REACTION RATE Non-catalytic metals such as Fe and Cu when added to the plating solution in low concentration may be successful in controlling the rate.

The reaction rate can also be controlled by decreas ing the pH to provide an acidic plating solution. In such acidic solutions, the metal ions, such as nickel ions, should be complexed with an alkylating agent, such as citric acid, to keep the metal ions in solution. A mixture of glacial acetic acid, and sodium acetate forms a suitable bufler for stabilizing the pH of such an acidic plating solution. I

Themetal plating process of this inventioncan be modifiedby any of the methods described in the above patents on the subject as well as in copending application Ser. No. 850,253, filed Aug. 14, 1969, now US.

' Pat. No. 3,548,943, and Ser. No. 835,243, filed June to give F/A,=l in the Pipe Nipple test described in copending application Ser. No. 840,826, filed July 10, 1969, now US. Pat. No. 3,386,524 was determined and the results are shown in table 5. Y

. TABLE Solution TF for F/A, 1

Table 1 (A (NiCl,-Na,l-[P0, solution) 330 Table 1 (A 63 g/l glycolate ion 336 Note: It can be seen that the addition of 63 g/l glycolate ion to the plating solution increases the temperature required to give unit PIA, by 36F. Since the rate doubles (or halves) every 18F, this represents a four-fold change in reaction rate constant.

Notable features of the present invention are the control of the reaction rate of the electroless metal process at a relatively high temperature. In consolidating relatively hot subsurface earth formations, relatively extensive depths of consolidation are achieved. In such a consolidation process, the metal platingprocess also aids in reducing corrosion and heat loss in or through tubing strings used in the wells, since, during the injection of the activating and plating fluids into the underground earth formations, the tubing strings are metalized by the process of the present invention. As these fluids are injected into the loose formations both the earth formations and the tubing are metaliz ed with nickel protective metal coatings, as well as other parts of the equipment and apparatus with which said metalizing fluids come in contact.

I claim as my invention: l. A method of plating metal onto a solid material by electroless metal plating, which method comprises:

' contacting the surface of said solid material with electroless metal plating activator solution to the extent required to provide thereon free metal surfaces that are adapted to catalyze an autocatalytic deposition of metal from an electroless metal plating solution; and

subsequently contacting said solid material with an electroless metal plating solution that contains a phosphite ion containing reducing agent and has a temperature of fromabout 250 to 400F.

2. :A method of consolidating an incompetent earth formation in which the temperature is from about 250 to 400F comprising treating the formation with an activating solution and thereafter treating the activated formation with an electroless metal plating solution containing a phosphite ion containing reducing agent 1 and having a temperature of from about 250 to 400F.

3. The method of claim 2 wherein the metal plating reaction is conducted within an indigenous subterranean earth formation having a temperature of from about 250 to 400F.

4. The method of claim 2 wherein the pH of the nickel plating solution is above 7 and the phosphite ion containing reducing agent is an alkali metal hydrogen h hit p The rnethod of claim 2 wherein the activating solution is an aqueous solution containing palladium chloride.

6. The method of claim 2 wherein the activator solution is an acidic aqueous solution containing palladium chloride and the metal plating solution is a nickel plat- 

2. A method of consolidating an incompetent earth formation in which the temperature is from about 250*F to 400*F comprising treating the formation with an activating sOlution and thereafter treating the activated formation with an electroless metal plating solution containing a phosphite ion containing reducing agent and having a temperature of from about 250*F to 400*F.
 3. The method of claim 2 wherein the metal plating reaction is conducted within an indigenous subterranean earth formation having a temperature of from about 250* to 400*F.
 4. The method of claim 2 wherein the pH of the nickel plating solution is above 7 and the phosphite ion containing reducing agent is an alkali metal hydrogen phosphite.
 5. The method of claim 2 wherein the activating solution is an aqueous solution containing palladium chloride.
 6. The method of claim 2 wherein the activator solution is an acidic aqueous solution containing palladium chloride and the metal plating solution is a nickel plating solution containing sodium hydrogen phosphite.
 7. The method of claim 2 wherein the nickel in the nickel plating solution is nickel amine complex.
 8. The method of claim 2 wherein a spacer fluid is injected into the earth formation between the activator and the metal plating solutions. 